Gas valves find ready use in the distribution and control of natural gas, propane, and fuel gas. Often such valves are used to allow or disallow gas to be drawn at individual distribution end-points, such as at residential or commercial buildings. Gas flow may be shut off because of safety concerns—e.g., leaks or supply line ruptures—or for other reasons, such as maintenance or billing issues.
Consequently, there are a number of known types of gas shut-off valves in use, including: manual shut-off valves, earthquake-sensitive shutoff valves, and excess-flow gas shutoff valves. See, e.g., Final Report Seismic Gas Shutoff Devices Excess Flow Gas Shutoff Devices, published in May 2004 by the California Housing and Community Development. The latter two types of gas shut-off valves in the preceding example list are types of automatic shut-off valves.
Further, there are a number of gas shut-off valves with some form of remote disconnect capability, either electrical or mechanical. Such valves may be integrated with the gas meter and, commonly, they rely for their operation on flow-rate sensing provided by the meter. There are known types of electronic valves that provide valve closure in response to locally or remotely generated RF commands. Other, more sophisticated examples include certain electronic valves manufactured by PANASONIC CORPORATION, for example. Such valves have met with success at least in the Japanese market.
However, providing for reliable long-term use of such valves in widespread distribution systems remains challenging. These challenges are particularly acute when one considers the harsher operating conditions associated with natural gas distribution in North America, and the increasing need for safe, low-maintenance or zero-maintenance installations.